An Internet forum is a discussion area on a website. Website members can post discussions and read and respond to posts by other forum members. A forum can be focused on nearly any subject and a sense of an online community, or virtual community, tends to develop among forum members.

This type of forum may also be called a message board, discussion group, bulletin board, or web forum, but it differs from a blog, the name for a web log, as a blog is usually written by one user and usually only allows for the responses of others to the blog material. A forum usually allows all members to make posts and start new topics.